This invention relates to a storage management system and a storage management method and, in particular, relates to management of copy functions of a storage system.
Recent widespread growth of IT technology has brought explosive increase in IT equipment including host computers. As a result, the abundance of IT equipment has produced a problem of difficulty in management of IT equipment. In such a circumstance, server virtualization techniques have been known as techniques that can achieve easy management of host computers.
A typical server virtualization technique is disclosed in VMware Virtual Machine File System: Technical Overview and Best Practices (Non-Patent Literature 1). This technique allows a virtualization control program (called hypervisor) to run on a host computer, so that the hypervisor constructs virtual computers (also called virtual machines (VMs)) different from the host computer in configuration, number and performance capability.
In this technique, the hypervisor manages a plurality of volumes to provide them for a single data storage area (called data store). In a meanwhile, in an environment that utilizes the server virtualization technique (called server virtualization environment), an OS (guest OS) running on a VM, and application programs and data therefore are unified into one or more image files (also called VM image files) of data.
A VM image file is stored in a data store and managed by the hypervisor. The VM image file is stored in a storage area in a storage system. The VM image file does not need to have a data structure of files managed by the file system.
In the meanwhile, there exist copy techniques by storage systems that replicate data in case of data loss. For example, U.S. Pat. No. 7,120,769 (Patent Literature 1) discloses that a storage system connected to a host computer simultaneously replicates volumes together in which data for application programs running on the host computer are stored using a copy function of the storage system.
This technique can restore the data for the application programs from both of a logical failure in an application program and a physical failure such as a fault in a drive in the storage system. Moreover, in the backup technique of a storage system, the storage system performs data copy required for backup; the load on the host computer can be suppressed. This technique achieves backups of a plurality of VMs without degradation in performance of the host computer (virtual servers).    Patent Literature 1 U.S. Pat. No. 7,120,769    Non-Patent Literature 1 VMware Virtual Machine File System: Technical Overview and Best Practices, VMware, Inc.